package Thread;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

// Callable 的用法
public class Demo26 {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        Callable<Integer> callable = new Callable<Integer>() {
            @Override
            public Integer call() throws Exception {
                int sum = 0;
                for (int i = 1; i <= 1000; i++) {
                    sum += i;
                }
                return sum;
            }
        };

        FutureTask<Integer> task = new FutureTask<>(callable);
        Thread t = new Thread(task);
        t.start();

        // 在线程 t 执行完之前，get会阻塞，直到 t 执行完了，计算好结果了
        System.out.println(task.get());
    }
}
